California Attorney General Xavier Becerra, like the reporters who cover him, has had a busy two years.

At a brisk clip of two new legal challenges every month, the state’s top law enforcement officer has turned the California Justice Department into one of the country’s most influential and prodigious battle stations of resistance to Washington policy. It’s not an original strategy. During the Obama presidency, attorneys general in Texas, Oklahoma and West Virginia regularly made an effort to trip up the White House in court (and made names for themselves in the process).

But under Becerra’s legal stewardship, California is now outgunning even Texas.

At last count, his office has sued the Trump administration 47 times (you can read about each here). That doesn’t include California’s legal requests that the court enforce prior victories against the federal government, nor cases in which the state came to the defense of Obama-era programs that the Trump administration declined to defend (counting those brings the total to 49, the number cited by Becerra’s office). Nor does it include, for instance, a suit filed by the University of California to block the Trump administration from rescinding protections for immigrants without legal status.

That’s to say nothing of the many “friends of the court” briefs, official regulatory comments and many other public declarations of California’s disapproval of D.C. policy.

It took Texas, reviled by Democrats as a symbol of vexatious legal obstructionism, eight years to file that many suits against Obama.

And so far, Becerra’s legal strategy has been successful.

“As an advocate on these issues it’s really quite amazing what he has accomplished,” said Christopher Gray, a spokesperson for the State Energy and Environmental Impact Center at New York University’s school of law. As of now, Becerra has won 16 cases and only lost two. Twenty-six more are pending, a testament to how slowly the wheels of justice turn.

But experts say the legal battle between blue states and the Trump administration may be entering a new phase. Many of the initial challenges by Becerra and other state attorneys general have hinged on questions of regulatory process—whether a federal agency followed the rules of administrative procedure as it set about transforming U.S. immigration law or environmental regulations. But now that the Trump administration has had time to correct errors or to move on from simply delaying implementation of Obama-era rules to introducing regulations of its own, a new round of battles over the future of environmental regulation, immigration enforcement, health policy and consumer protection are set to begin.

Becerra’s unprecedented show of legal force is part of a nationwide trend. According to data collected by Paul Nolette, a political scientist at Marquette University, states have filed 71 joint lawsuits against the administration in just two years. That’s at least 10 more than all the state challenges filed against the White House during the entirety of Obama’s two-term presidency.

Democrats argue this is proof of the Trump administration’s disregard for the rule of law. Nolette sees it as part of a larger trend in which attorneys general have become partisan figures of increasing national importance.

Prior to the Obama administration, state attorneys general “saw themselves as legal representatives of their own states,” said Nolette. “Now it’s far more about taking actions consistent with their party and what their policy priorities are.”

Constantly suing the White House has been a successful political strategy for Becerra too. Despite taking some positions at home that put him at odds with many progressives, California’s soft-spoken attorney general has become a regularly featured talking head on MSNBC, a figurehead of blue America’s opposition to the president. Earlier this year he was tapped to give the Spanish language rebuttal to President Trump’s state of the union speech.

Republicans have slammed Becerra for using the office to advance his political brand—a common line of attack from Becerra’s general election challenger, Republican Steven Bailey, last year. Alas, Becerra won by nearly 30 percentage points.

For a Democrat in California, suing the Trump administration is “almost all upside,” said Nolette. “You get media attention, (and) of course, you could win.”

Becerra’s office has been doing plenty of that. But as even some political allies concede, that has as much to do with the Trump administration’s rapid-fire approach to de-regulation as Becerra’s legal strategizing.

Becerra “has been very effective” in pushing back against the White House, said Gray from New York University. But “the Trump administration is just so incompetent you almost lose that story because losing on administrative procedure is such a low bar.”

Since the 1940s, federal rulemaking has been governed by the Administrative Procedure Act, which requires agencies to be transparent about how they come up with new regulations and to offer reasonable justifications for why those new rules are necessary. Becerra and his Democratic counterparts in other states have regularly attacked the Trump administration in court for, they argue, failing to check those boxes.

That has been particularly true in areas of environmental policy, where both the Interior Department and the Environmental Protection Agency have much broader rulemaking authority than many other federal agencies. Just under half of all the challenges filed by California against the administration relate to environmental regulation.

In the last year, efforts by the Trump administration to weaken the Affordable Care Act, place a citizenship question on the 2020 Census, and overhaul a series of environmental laws were all swatted down in court over procedural objections.

But some experts say that once the Trump administration deals with those procedural complaints, it’s possible that California will have a harder time finding plausible legal justifications to sue.

“We’re waiting on a couple of big ones,” said Gray. “We’re in a bit of a holding pattern right now.”

Whether the administration fares better in court depends on whether their new policies are as “substantively sloppy as the procedural moves they’ve made,” said Ann Carlson, an environmental law professor at UCLA.

It will also depend on the courts, which are growing ever more likely to rule in the president’s favor. According to the conservative Heritage Foundation, the president has appointed 96 judges, including two Supreme Court Justices. That’s compared to 78 judicial appointments by Obama over eight years.

Still, the raft of lawsuits filed by Becerra and other state attorneys general may have already achieved their intended effect.

“The procedural battles are significantly slowing down Trump’s regulatory assault,” said Carlson, “and by the time the rules gets passed we’re going to be very close to a new election.”